Mercurial > dropbear
view libtomcrypt/src/pk/asn1/der/sequence/der_decode_sequence_flexi.c @ 1385:6c92e97553f1 fuzz
Add a flag whether to longjmp, missed that last commit
author | Matt Johnston <matt@ucc.asn.au> |
---|---|
date | Thu, 01 Jun 2017 21:30:26 +0800 |
parents | 0cbe8f6dbf9e |
children | f849a5ca2efc |
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/* LibTomCrypt, modular cryptographic library -- Tom St Denis * * LibTomCrypt is a library that provides various cryptographic * algorithms in a highly modular and flexible manner. * * The library is free for all purposes without any express * guarantee it works. * * Tom St Denis, [email protected], http://libtomcrypt.com */ #include "tomcrypt.h" /** @file der_decode_sequence_flexi.c ASN.1 DER, decode an array of ASN.1 types with a flexi parser, Tom St Denis */ #ifdef LTC_DER static unsigned long fetch_length(const unsigned char *in, unsigned long inlen) { unsigned long x, y, z; y = 0; /* skip type and read len */ if (inlen < 2) { return 0xFFFFFFFF; } ++in; ++y; /* read len */ x = *in++; ++y; /* <128 means literal */ if (x < 128) { return x+y; } x &= 0x7F; /* the lower 7 bits are the length of the length */ inlen -= 2; /* len means len of len! */ if (x == 0 || x > 4 || x > inlen) { return 0xFFFFFFFF; } y += x; z = 0; while (x--) { z = (z<<8) | ((unsigned long)*in); ++in; } return z+y; } /** ASN.1 DER Flexi(ble) decoder will decode arbitrary DER packets and create a linked list of the decoded elements. @param in The input buffer @param inlen [in/out] The length of the input buffer and on output the amount of decoded data @param out [out] A pointer to the linked list @return CRYPT_OK on success. */ int der_decode_sequence_flexi(const unsigned char *in, unsigned long *inlen, ltc_asn1_list **out) { ltc_asn1_list *l; unsigned long err, type, len, totlen, x, y; void *realloc_tmp; LTC_ARGCHK(in != NULL); LTC_ARGCHK(inlen != NULL); LTC_ARGCHK(out != NULL); l = NULL; totlen = 0; /* scan the input and and get lengths and what not */ while (*inlen) { /* read the type byte */ type = *in; /* fetch length */ len = fetch_length(in, *inlen); if (len > *inlen) { err = CRYPT_INVALID_PACKET; goto error; } /* alloc new link */ if (l == NULL) { l = XCALLOC(1, sizeof(*l)); if (l == NULL) { err = CRYPT_MEM; goto error; } } else { l->next = XCALLOC(1, sizeof(*l)); if (l->next == NULL) { err = CRYPT_MEM; goto error; } l->next->prev = l; l = l->next; } /* now switch on type */ switch (type) { case 0x01: /* BOOLEAN */ l->type = LTC_ASN1_BOOLEAN; l->size = 1; l->data = XCALLOC(1, sizeof(int)); if ((err = der_decode_boolean(in, *inlen, l->data)) != CRYPT_OK) { goto error; } if ((err = der_length_boolean(&len)) != CRYPT_OK) { goto error; } break; case 0x02: /* INTEGER */ /* init field */ l->type = LTC_ASN1_INTEGER; l->size = 1; if ((err = mp_init(&l->data)) != CRYPT_OK) { goto error; } /* decode field */ if ((err = der_decode_integer(in, *inlen, l->data)) != CRYPT_OK) { goto error; } /* calc length of object */ if ((err = der_length_integer(l->data, &len)) != CRYPT_OK) { goto error; } break; case 0x03: /* BIT */ /* init field */ l->type = LTC_ASN1_BIT_STRING; l->size = len * 8; /* *8 because we store decoded bits one per char and they are encoded 8 per char. */ if ((l->data = XCALLOC(1, l->size)) == NULL) { err = CRYPT_MEM; goto error; } if ((err = der_decode_bit_string(in, *inlen, l->data, &l->size)) != CRYPT_OK) { goto error; } if ((err = der_length_bit_string(l->size, &len)) != CRYPT_OK) { goto error; } break; case 0x04: /* OCTET */ /* init field */ l->type = LTC_ASN1_OCTET_STRING; l->size = len; if ((l->data = XCALLOC(1, l->size)) == NULL) { err = CRYPT_MEM; goto error; } if ((err = der_decode_octet_string(in, *inlen, l->data, &l->size)) != CRYPT_OK) { goto error; } if ((err = der_length_octet_string(l->size, &len)) != CRYPT_OK) { goto error; } break; case 0x05: /* NULL */ /* valid NULL is 0x05 0x00 */ if (in[0] != 0x05 || in[1] != 0x00) { err = CRYPT_INVALID_PACKET; goto error; } /* simple to store ;-) */ l->type = LTC_ASN1_NULL; l->data = NULL; l->size = 0; len = 2; break; case 0x06: /* OID */ /* init field */ l->type = LTC_ASN1_OBJECT_IDENTIFIER; l->size = len; if ((l->data = XCALLOC(len, sizeof(unsigned long))) == NULL) { err = CRYPT_MEM; goto error; } if ((err = der_decode_object_identifier(in, *inlen, l->data, &l->size)) != CRYPT_OK) { goto error; } if ((err = der_length_object_identifier(l->data, l->size, &len)) != CRYPT_OK) { goto error; } /* resize it to save a bunch of mem */ if ((realloc_tmp = XREALLOC(l->data, l->size * sizeof(unsigned long))) == NULL) { /* out of heap but this is not an error */ break; } l->data = realloc_tmp; break; case 0x0C: /* UTF8 */ /* init field */ l->type = LTC_ASN1_UTF8_STRING; l->size = len; if ((l->data = XCALLOC(sizeof(wchar_t), l->size)) == NULL) { err = CRYPT_MEM; goto error; } if ((err = der_decode_utf8_string(in, *inlen, l->data, &l->size)) != CRYPT_OK) { goto error; } if ((err = der_length_utf8_string(l->data, l->size, &len)) != CRYPT_OK) { goto error; } break; case 0x13: /* PRINTABLE */ /* init field */ l->type = LTC_ASN1_PRINTABLE_STRING; l->size = len; if ((l->data = XCALLOC(1, l->size)) == NULL) { err = CRYPT_MEM; goto error; } if ((err = der_decode_printable_string(in, *inlen, l->data, &l->size)) != CRYPT_OK) { goto error; } if ((err = der_length_printable_string(l->data, l->size, &len)) != CRYPT_OK) { goto error; } break; case 0x16: /* IA5 */ /* init field */ l->type = LTC_ASN1_IA5_STRING; l->size = len; if ((l->data = XCALLOC(1, l->size)) == NULL) { err = CRYPT_MEM; goto error; } if ((err = der_decode_ia5_string(in, *inlen, l->data, &l->size)) != CRYPT_OK) { goto error; } if ((err = der_length_ia5_string(l->data, l->size, &len)) != CRYPT_OK) { goto error; } break; case 0x17: /* UTC TIME */ /* init field */ l->type = LTC_ASN1_UTCTIME; l->size = 1; if ((l->data = XCALLOC(1, sizeof(ltc_utctime))) == NULL) { err = CRYPT_MEM; goto error; } len = *inlen; if ((err = der_decode_utctime(in, &len, l->data)) != CRYPT_OK) { goto error; } if ((err = der_length_utctime(l->data, &len)) != CRYPT_OK) { goto error; } break; case 0x30: /* SEQUENCE */ case 0x31: /* SET */ /* init field */ l->type = (type == 0x30) ? LTC_ASN1_SEQUENCE : LTC_ASN1_SET; /* we have to decode the SEQUENCE header and get it's length */ /* move past type */ ++in; --(*inlen); /* read length byte */ x = *in++; --(*inlen); /* smallest SEQUENCE/SET header */ y = 2; /* now if it's > 127 the next bytes are the length of the length */ if (x > 128) { x &= 0x7F; in += x; *inlen -= x; /* update sequence header len */ y += x; } /* Sequence elements go as child */ len = len - y; if ((err = der_decode_sequence_flexi(in, &len, &(l->child))) != CRYPT_OK) { goto error; } /* len update */ totlen += y; /* link them up y0 */ l->child->parent = l; break; default: /* invalid byte ... this is a soft error */ /* remove link */ l = l->prev; XFREE(l->next); l->next = NULL; goto outside; } /* advance pointers */ totlen += len; in += len; *inlen -= len; } outside: /* rewind l please */ while (l->prev != NULL || l->parent != NULL) { if (l->parent != NULL) { l = l->parent; } else { l = l->prev; } } /* return */ *out = l; *inlen = totlen; return CRYPT_OK; error: /* free list */ der_sequence_free(l); return err; } #endif /* $Source: /cvs/libtom/libtomcrypt/src/pk/asn1/der/sequence/der_decode_sequence_flexi.c,v $ */ /* $Revision: 1.25 $ */ /* $Date: 2006/11/26 02:25:18 $ */